Bar codes have been widely used in the prior art, in general for POS merchanidizing applications in supermarkets, etc. The bar code may be printed on adhesive labels, which are then attached to surfaces of respective articles which are to be sold, or may be directly printed on a surface of the article. In the present specification, the term "bar code label" is used for convenience of description to signify a printed bar code pattern, irrespective of whether the pattern has been directly printed on a surface of an article or has been printed on a separate label which is then attached to the article. To avoid misunderstanding, the term "bar code label" should be understood to signify the entire label, which consists of an array of parallel bars and, generally, a line of numerals. The term "bar code region" as used herein signifies only the array of parallel bars in the bar code label. The bar code labels may be disposed at various arbitrary positions and inclinations upon the articles, and there may be two or more bar code labels closely mutually adjacent on the surface of each article. As a result, it has been difficult to provide an apparatus which will enable the bar code to be read and decoded in a rapid and reliable manner, without manual adjustment of the way in which each bar code label is scanned in order to be read. To overcome this problem, various proposals for bar code readers have been made in the prior art. THese generally are based upon scanning a bar code pattern in a plurality of different directions, to ensure that at least one correct scan (e.g. by a light beam of an optical bar code reading device) across the bar code label will occur. Here, the term "correct scan" signifies a scan which intersects all of the bars of the bar code pattern, and is oriented substantially perpendicular to the direction of elongation of the bars. Such prior art proposals are summarized in the Japanese magazine Nikkei Electronics of Dec. 22, 1980, page 142 in an article entitled "Types of Bar Code Reader".
However there are no prior art examples of a method or apparatus for finding and reading a bar code region of a source image, where the bar code region is represented as data within successive data values of a signal that has been obtained by raster scanning of the source image. Such an image data signal is for example produced in the prior art by facsimile scanning.